THE GASTRIC RESPONSE OF MAN TO AN ACID TEST MEAL

Abstract

The gastric secretory response to the instillation of 300 ml. of 0.5% hydrochloric acid was investigated 30 times in eight subjects by withdrawing six samples at 20 min. intervals and measuring the acid concentration. In six experiments duodenal regurgitation was prevented by constant duodenal suction. As this did not delay the fall in acidity ordinarily observed it was concluded that regurgitation was not essential for this process. In 14 experiments phenol red was added to the instilled solution and the amount of dilution was measured. It was found that on the average the decrease in concentration of the dye was the same as that of the acid although there were frequent small discrepancies. It was concluded that instillation of acid into the human stomach stimulates one or more secretions whose net effect is to reduce the acidity by dilution.